PhD Course
Hands-on Continuum Mechanics with COMSOL
Luciano Teresi
Dip. Matematica e Fisica, Università Roma Tre
PhD Course
Luciano Teresi
Dip. Matematica e Fisica, Università Roma Tre
Organizers: the course is organized in partnership with three PhD Schools:
• PhD on Mathematics, Dept. Mathematics & Physics, University Roma Tre;
• PhD on Theoretical & Applied Mechanics, Dept. Aeronautical & Mechanical Engineering, Sapienza University, Roma;
• PhD on Structural & Geotechnical Engineering, Dept. of Structural and Geotechnical Engineering, Sapienza University, Roma.
Schedule: June 2023;
Four lectures: Mon 19, Wed 21, Fri 23, Mon 26, from 9:00 to 13:00 (break included).
Venue: Lecture Room 36, first floor of building D (aka, DICEA building), at Engineering School of Sapienza University, via Eudossiana 18, Rome.
Teaching Modalities: all lectures will be in hybrid mode (in person, streaming, playback); streaming and playback with M-Teams. Due to the "hands-on" approach, participants are recommended to attend in person.
Goal: understand the fundamentals of continuum mechanics through worked examples, with a focus on the relations between mechanics and differential geometry. Participants will tackle some typical problems of continuum mechanics, and will learn to implement a given problem using the weak formulation into the COMSOL software and to discuss the solution.
Software: a trial license for the latest COMSOL version can be dowloaded at the following link: Get your trial license for COMSOL
Synopsis of lectures (tentative program)
1) Browse a model of nonlinear solid mechanics, from the implementation to the solution.
A first glance at the fundamentals of continuum mechanics: Kinematics, Constitutive, and Balance laws.
Differential form (strong) versus Integral form (weak).
What is a test function (aka, virtual displacement or virtual velocity)
Worked example: large deformations of a hyperelastic solid under loadings.
2) Material Versus Spatial description.
A continuum body as a differentiable manifold.
Tell the difference between tensors: strain tensor versus stress tensor.
Geometric elements; change of densities.
Pull back & push forward of scalar, vector and tensor fields.
3) Solid mechanics versus Fluid mechanics
Kinematical constraints; isochoric motion.
Reference stress (Piola) & Actual stress (Cauchy).
Polar decomposition theorem; eigen-space of the stress tensor and of the strain tensor
4) Non linear solid mechanics and the Elastic Metric
Worked example: large deformations of a hyperelastic solid under distortions. The notion of Elastic metric and Target metric.
5) Material response
Worked example: from elastic energy to the constitutive law for the stress.
Transversely isotropic materials. Fiber reinforced materials.
Worked example: fiber reinforced hyperelastic solid under traction.
6) Fluid dynamics
Tackling Navier-Stokes equations.
Worked examples: fluid in a channel; fluid around an obstacle.
7) Fluid-Structure interactions - theory
Worked examples: understand the moving mesh technique; how to write the problem of a beam immersed in a fluid.
8) Fluid-Structure interactions - practice
Worked example: implement and solve the problem of an oscillating beam immersed in a fluid.